Endophytic fungi as partners in a holistic approach to enhance plant growth and stress tolerance for sustainable agriculture

erhaps the most widely used agents of biological plant protection are endophytic fungal symbionts (endophytes) of forage and turfgrasses. These are fungi of the family Clavicipitaceae, which grow between host cells in vegetative tissues, ovules, and seeds of systemically infected grass plants. The existence of these endophytes was not fully appreciated until recent years, although the protection they provide against insect damage (Fig. 1) and drought contributes to the superior agronomic qualities of favorite pasture grasses in North America, Australia, and New Zealand. Unfortunately for livestock farmers, these endophytes also provide a degree of protection from grazing mammals. In 1977, Bacon et al. (2) reported that the grass Festuca arundinacea var. genuina Schreb. (hexaploid tall fescue) had a fungal endophyte related to Epichloe typhina (Pers.:Fr.) Tul., and that this endophyte— now known as Neotyphodium coenophialum (Morgan-Jones & Gams) Glenn, Bacon, & Hanlin—was responsible for toxicosis suffered by livestock grazing the grass. Epichloe species were known for many decades (44), but reports relating that nonpathogenic endophytes could be detrimental to livestock provided new impetus for intensive studies, making the grass–endophyte associations among the best characterized symbioses in biology. Less than two decades of research have yielded a rich body of knowledge about these symbioses: their secondary product chemistry, ecology, evolution, genetics, and molecular biology; their ecological roles as protectants from insect and vertebrate herbivores, pathogenic fungi and nematodes, and drought; and their effects on host growth and competitiveness. The endophytes produce numerous alkaloids, some of which are unrelated to any known from plants or other fungi. Their genetic and evolutionary complexity is extraordinary. They were the first fungi genetically documented as interspecific hybrids (47,53). Meanwhile, molecular genetic techniques were applied to the endophytes of tall fescue and other grasses, bringing us closer to the prospect of reducing or eliminating their toxicosis to livestock while continuing to employ their bioprotective qualities.

It is a known fact that the bacterial and fungal endophytes inhabit the plant tissues besides aiding in the better growth and health of the plants. The bark and leaves of Taxus wallichiana have drawn a lot of interest in recent years since they are the richest source of taxol, an anticancer drug. As it is a slow-growing tree that can only be regenerated via vegetative propagation, it has been classified as a critical rare species due to its extensive collection for medicinal and other purposes. Nonetheless, the use of endophytes as plant growth promoters is gaining much importance among environmentalists and agronomists because of their imperative role in crop production. Even then, there is hardly any information available regarding the growth-promoting endophytes isolated from bark and leaves associated with T. wallichiana commonly known as Himalayan Yew. Therefore, the present study was undertaken to isolate fungal and bacterial endophytes from T. wallichiana and to classify the growth-promoting properties of these endophytes. In total, seven fungal and ten bacterial endophytes were obtained from different parts of T. wallichiana. All of the isolated fungal and bacterial endophytes produced indole acetic acid while most of them also produced ammonia. Besides, the fungal and bacterial endophytes were also screened for antimicrobial and various enzymatic activities. Based on the above results, the two fungal endophytes were selected for their possible ability to promote seed growth. The results showed that the fungal endophytes isolated from T. wallichiana played an active role in increasing growth in other plant species and therefore, can be used as potential plant growth promoters.

Endophytic fungi of crops can promote plant growth through various mechanisms of action (i.e., improve nutrient uptake and nutrient use efficiency, and produce and modulate plant hormones). The genus Brassica includes important horticultural crops, which have been little studied in their interaction with endophytic fungi. Previously, four endophytic fungi were isolated from kale roots (Brassica oleracea var. acephala), with different benefits for their host, including plant growth promotion, cold tolerance, and induction of resistance to pathogens (Xanthomonas campestris) and pests (Mamestra brassicae). In the present work, the molecular and morphological identification of the four different isolates were carried out, describing them as the species Acrocalymma vagum, Setophoma terrestris, Fusarium oxysporum, and the new species Pyrenophora gallaeciana. In addition, using a representative crop of each Brassica U’s triangle species and various in vitro biochemical tests, the ability of these fungi to promote plant growth was described. In this sense, the four fungi used promoted the growth of B. rapa, B. napus, B. nigra, B. juncea, and B. carinata, possibly due to the production of auxins, siderophores, P solubilization or cellulase, xylanase or amylase activity. Finally, the differences in root colonization between the four endophytic fungi and two pathogens (Leptosphaeria maculans and Sclerotinia sclerotiorum) and the root glucosinolate profile were studied, at different times. In this way, how the presence of progoitrin in the roots reduces their colonization by endophytic and pathogenic fungi was determined, while the possible hydrolysis of sinigrin to fungicidal products controls the colonization of endophytic fungi, but not of pathogens.

Phosphorus (P) is the primary nutrient element needed for overall plant growth and crop productivity. The global farming practices are majorly dependent on the use of synthetic phosphate fertilizers. But the cost of synthetic fertilizers, their associated negative impact on human and environment, and frequent precipitation and immobilization of phosphorus in soil have led agriculturalists to look for alternative strategies that could enhance plant growth by maintaining soluble phosphorus pool in soil. Microbial communities, including fungi, possess the ability for phosphate solubilization and mineralization. In soil, P-solubilizing fungi constitute about 0.1–0.5% of the total fungal populations. Among them endophytic fungi are the major contributors. Endophytes represent the soil microbial population that can colonize plants without inducing any apparent disease symptoms. The major endophytic P-solubilizing fungi belong to the genera Penicillium, Aspergillus, Piriformospora, Curvularia, and another class of endophytic symbionts arbuscular mycorrhizal (AM) fungi. P-solubilizing endophytic fungi are more competitive and aggressive colonizers than non-endophytic microbes. Considering the vast array of benefits of using endophytic fungi for plant P nutrition, this chapter focuses on the role of endophytic and mycorrhizal fungi in P-solubilization and mineralization, their mechanisms involved, development and mode of application of endophytic fungal inoculants, and their various mechanisms of plant growth promotion and crop productivity.

Endophytic fungi are commonly found in the root endosphere and can enhance plant growth through various mechanisms. The aim of this study was to isolate cultivable endophytic fungi associated with the roots of Tamarix ramosissima and to evaluate their plant growth promoting properties. About 35 isolated fungal endophytes belonging to the Ascomycota from four different genera were isolated from the endosphere of T. ramosissima: Alternaria, Aspergillus, Fusarium and Talaromyces. These fungal endophytes showed different abilities to solubilize phosphate and produce indole-3-acetic acid (IAA). The fungal isolates of T. allahabadensis (T3) and A. niger (T4) showed different efficiency in solubilizing phosphate. Almost all fungal isolates were able to produce IAA, and the highest value (0.699 μg/ml) was found in the isolate of F. solani (T11). Inoculation of wheat seeds with endophytic fungi significantly increased the initial growth of wheat roots. The results showed that inoculation with the endophytic fungus A. fumigatus T15 significantly increased root length by 75%. The extensive root system of T. ramosissima may be due to symbiosis with IAA-producing endophytic fungi, which enhance root development and water uptake in dry conditions. These fungi can also boost soil phosphorus levels, promoting plant growth.

Plant microbe-interactions contribute in mitigating abiotic environmental stresses in plants. Salinity stress is one of major factor in reducing agricultural productivity. Recently, the use of endophytic fungi has proved as one of the approaches that can help plant growth under salt stress. Therefore, the objective of this study was to isolate halotolerant endophytic fungi and elevate their potential to mitigate salt stress in Vigna radiata. Endophytic fungi were isolated from asymptomatic parts of Vachellia nilotica and screened for plant growth-promoting attributes such as IAA production, phosphate solubilization, siderophore production, and halotolerance. Based on growth-promoting characteristics and halotolerance, Aspergillus niger VN2 was selected and colonized in V. radiata. The colonized plants were exposed to different salt concentrations (150 mM, 200 mM, and 250 mM NaCl) to evaluate the effect of A. niger VN2 in mitigating salt stress. The effects of A. niger VN2 colonization on physiological, biochemical, and molecular parameters were assessed. In the present study, an endophytic fungus Aspergillus niger VN2 isolated from Vachellia nilotica exhibited good plant growth promotion properties and halotolerance. A. niger VN2 produced IAA (148.32 ± 2.34µg/ml IAA), solubilized phosphate, and produced hydroxamate type siderophore (72.66% SU). It also exhibited ACC deaminase ability (134.40 ± 5.45µmolα-ketobutyrate/h/mg protein), and could tolerate up to 15% NaCl. Colonization of A. niger VN2 in V. radiata enhanced salt tolerance, and resulted in increased root and shoot length, biomass, leaf number, chlorophyll content, relative water content, and protein content in salt stressed plants. DPPH scavenging and endogenous IAA levels also increased in treated plants. Oxidative stress parameters viz. proline, electrolyte leakage, and malondialdehyde, were found to decrease in VN2 colonized plants. Fluorescent microscopy studies revealed VN2 colonized plants showed increased cell survival and lowered glutathione and hydrogen peroxide under salt stress. Comet assay was used for determining the genoprotective effect of A. niger VN2. Colonization of A. niger VN2 reduced DNA tail length, % tail DNA, tail moment, and olive tail moment in plants exposed to salt stress. The difference in biochemical molecules viz. protein, carbohydrates, lipid, and nucleic acid in colonized and non-colonized plants under salt stress was revealed by FT-IR spectroscopy and validated by PCA, which showed that A. niger VN2 mitigated salt-induced changes, as colonized samples clustered closely under both conditions. From the current study, it can be concluded that colonization of endophytic fungus A. niger VN2 promotes plant growth and can mitigate salt stress in V. radiata by regulating oxidative stress.

Endophytic fungi enhance the plant’s ability to tolerate stressful conditions including heavy metal stress via secretion of numerous secondary metabolites. However, the role of heavy metal resistant fungal endophytes in growth promotion of plants in extreme environments is need to be understood. Therefore, eight endophytic fungal isolates having arsenic tolerance potential up to 2000 ppm explored from the arsenic stressed plants were subjected to various in vitro growth promoting traits viz., phytohormones production, phosphate solubilization, siderophore production, ammonia production, HCN production and ACC deaminase activity under normal and arsenic stress (100 ppm) condition. Indole acetic acid produced by fungal endophytes ranged between 120-610 μg/ mL, which was reduced to 50-340 μg/ mL when they were grown on arsenic induced medium. In the siderophore production test, fungal isolate S3P1S1 produced significantly higher siderophore (96 ± 0.002 μmol) compared to other isolates and reference culture. In addition, HCN production was observed in only one isolate. Therefore, present study clearly identified specific traits in the fungal endophytes, which make them good candidates as PGPR and might contribute to plant adaption to arsenic contaminated soils. These fungal endophytes, possessing metal tolerance as well growth promoting properties under in vitro conditions could have vital implications for the agricultural sector if used as biofertilizer.

Simple Summary‘Chujv’, ‘Fubai jv’, ‘Hangbai jv’, ‘Jinsi huangjv’, and ‘Nannong jinjv’ are the five most popular tea chrysanthemum cultivars in China. Sustained monoculture often leads to plant growth inhibition and quality deterioration, causing significant economic losses to farmers. Endophytic microbes play pivotal roles in plant growth, development, and diversification. However, the effects of endophytes in various tea chrysanthemum cultivars under field conditions remain unknown. In the present study, the community composition and diversity of endophytic bacteria and fungi in five commercially popular tea chrysanthemums were characterized using high-throughput sequencing and culture-dependent methods. The endophytic microbiomes significantly differed across tea chrysanthemum cultivars and organs (stems and leaves). Importantly, it was indicated by the field study that 4 of 42 isolated endophytes could significantly promote tea chrysanthemum yield. These findings offer novel insights into the endophytic microbiomes of tea chrysanthemums and their potential applications in sustainable cultivation.The endophytic microbiomes significantly differed across tea chrysanthemum cultivars and organs (stems and leaves). The most abundant endophytic bacterial genera were Pseudomonas, Masillia, and Enterobacter in the leaves and Sphingomonas and Curtobacterium in the stems of the five cultivars. Meanwhile, the most abundant endophytic fungal genera in the leaves and stems of the five tea chrysanthemums were Alternaria, Cladosporium, and Sporobolomyces. Specifically, Rhodotorula was dominant in the leaves of ‘Jinsi huangjv’ and Paraphoma was dominant in the stems of ‘Jinsi huangjv’. In all cultivars, the diversity and richness of endophytic bacteria were higher in leaves than in stems (p < 0.05). The highest diversity and richness of endophytic bacteria were recorded in ‘Chujv’, followed by ‘Jinsi huangjv’, ‘Fubai jv’, ‘Nannong jinjv’, and ‘Hangbai jv’. Meanwhile, endophytic fungi were less pronounced. Twenty-seven and 15 cultivable endophytic bacteria and fungi were isolated, four isolated endophytic bacteria, namely, CJY1 (Bacillus oryzaecorticis), CY2 (Pseudomonas psychrotolerans), JSJ7, and JSJ17 (Enterobacter cloacae) showed higher indole acetic acid production ability. Further field studies indicated that inoculation of these four endophytic bacteria not only promoted plant growth and yield but also increased total flavonoids, chlorogenic acid, luteolin, and 3,5-dicoffeylquinic acid levels in the dry flowers of tea chrysanthemums.

Fungus-derived opine enhances plant photosynthesis

Plant growth-promoting effects and possible mechanisms of a plant endophytic fungus Aureobasidium sp. JRF1.

Agricultural productivity suffers a heavy loss due to plant pathogens, insect pests and various abiotic stresses. Agriculture being the world’s largest economic sector, it is the need of time to find and establish the ideal strategy for sustainable agriculture and improvement in crop growth. Endophytes are microorganisms that asymptomatically grow within the plant tissues without causing any disease to the host. Endophytic fungi live in symbiotic association with plants and play an important role in plant growth promotion, higher seed yield and plants resistant to various biotic, abiotic stresses and diseases. Many are able to produce antimicrobial compounds, plant growth hormones and various agrochemical bioactive metabolites. These mycoendophytes hold enormous potential for the development of eco-friendly and economically viable agricultural products. In this review we focused on the endophytic fungi recovered from different medicinal plants, their active principles involved in plant growth enhancement and the applications of fungal endophytes in agriculture. Moreover, we also discussed about endophytic fungi and their pragmatic approach towards sustainable food and agriculture.

Escalation of sugarcane productivity to support self-sufficiency in sugar in 2014 should be followed with improving environmentally friendly cultivation sys-tem. One of the alternatives is the use of endophyte. Endophyte is a microorganism naturally integrated with healthty plant and lives inside plant tissues without giving any negative effects. Endophyte could act as plant growth promotor, increase yield through phytohormone production and nutrition supplyer, and as soil contaminant neutralizer so it increases phyto-remediation and plant resistance against abiotic stress, and acts as biocontrol agent for pests and diseases. Even through biotechnology evolution, endophyte is used to produce antibiotic for medicine or pharmacy, biomass, biofuel, and media for transgenic resistance to insect pest or pathogen. Bacterial endohyte Acetobacter diazotrophicus (Syn. : Gluconacetobacter diazotrophicus ) provides 60-80% of Nitrogen required by sugarcane through N 2 fixation from air, so it suits as source of biofertilizer. In addition, there are many endophytes found as root or plant growth promotor and as biocontrol agent for pathogen. In Indonesia, research on the role of endophyte on sugarcane is still limited, hence it needs to reveal and determine the potential of endophyte to improve sugarcane health as wel as supporting acceleration of increasing sugar production. Keyword: endophyte, sugarcane, environment, pathogen, nutrition

Background Endophytic fungi are microorganisms that live within plant tissues without causing disease symptoms, playing a crucial role in enhancing plant resistance against pathogens and insect pests while simultaneously promoting plant growth through various mechanisms. This systematic review analyzes 47 research articles published between 2020 and 2025, examining the role of endophytic fungi. The literature search was conducted in Scopus and PubMed databases using relevant keywords, initially yielding 2,730 records that were subsequently filtered based on four inclusion criteria: (i) Studies must examine interactions between endophytic fungi and plants; (ii) studies must include plant defense mechanisms induced by endophytic fungi; (iii) studies must demonstrate the fungi’s entomopathogenic capabilities; and (iv) studies must show the fungi’s ability to enhance plant growth. Results The analysis revealed that Beauveria bassiana was the most extensively studied endophytic fungus species (59.15% of studies), particularly in food crops such as rice, corn, and legumes. The most frequently reported plant resistance mechanisms involved activation of ISR/SAR pathways and increased production of defensive compounds. As entomopathogens, endophytes demonstrated high efficacy against target insects through cuticle colonization and toxin production, while their growth-promoting capabilities were evident through enhanced nutrient uptake and phytohormone production. A systemic approach that integrates all these aspects can provide more effective and sustainable pest control solutions, yet the percentage discussed in this study is still limited to only 21.27%, even though the integration of the three observation parameters is considered more strategic and efficient. However, endophytic fungi’s effectiveness was found to be highly dependent on environmental factors and plant genotype. Conclusion Although research on endophytic fungi continues to expand, integrative evaluations of their roles in plant defense, insect suppression, and growth enhancement remain limited.The study recommends: (1) exploring indigenous isolates from different ecosystems; (2) integrating multifunctional approaches using endophytic fungi; and (3) developing more stable bioformulations. These findings provide an important foundation for utilizing endophytic fungi as multifunctional biocontrol agents in sustainable agriculture.

Gibberellins producing endophytic Aspergillus fumigatus sp. LH02 influenced endogenous phytohormonal levels, isoflavonoids production and plant growth in salinity stress

World agriculture depends in part on the crop-associated microbiome for improved plant growth, health, and productivity. In particular, endophytic fungi (EF) with plant growth–promoting activities fulfill some of these roles and are central as bioinoculant agents. In the case of arbuscular mycorrhizal fungi (AMF), they form a symbiosis with their host plants, enhancing the uptake of water, phosphorus, nitrogen, and other micronutrients, while the plants provide them with photosynthates. This work reviews the differences in the colonization of internal plant niches between these beneficial fungi, as well as other distinctive ecological traits. It also explores mechanisms of seedborne vertical transmission in AMF and their classification. Genomic and transcriptomic advances in fungal endophytes are highlighted, shedding light on genes and expression profiles that define their lifestyle and plant associations. In addition, recent studies on their abilities to promote plant growth are analyzed, especially focusing on Trichoderma spp., Epichloë spp., Serendipita indica (formerly Piriformospora indica), and entomopathogens like Beauveria spp. and Metarhizium spp. Finally, the multiple interactions among EF, AMF, and other members of the plant microbiome—notably plant growth-promoting bacteria (PGPB)—are discussed, emphasizing how these organisms synergistically benefit the host. A deeper understanding of these fungi and their plant-beneficial effects should facilitate commercialization and help farmers achieve sustainable production, especially under challenges posed by global climate change.